Computational comparison of cation coordination to human prion peptide models

Area of Science:

• Biochemistry
• Computational Chemistry
• Structural Biology

Background:

• The human prion protein (PrP) contains a copper-binding octapeptide region crucial for its function.
• Understanding metal ion coordination in PrP is vital for elucidating its biological roles and disease mechanisms.

Purpose of the Study:

• To computationally compare the coordination of various metal cations (Cu(II), Co(II), Rh(III), Ir(III), Ni(II), Pd(II), Pt(II), Zn(II)) to the PrP octapeptide region.
• To identify potential substitutes for Cu(II) in Nuclear Magnetic Resonance (NMR) spectroscopic studies.

Main Methods:

• Structural optimization using computational methods.
• Analysis of coordination modes and preferences of different metal cations.
• Evaluation of NMR spectroscopic characteristics of potential metal substitutes.

Main Results:

• Co(II) and Rh(III) showed coordination modes most similar to Cu(II).
• Ni(II), Pd(II), and Pt(II) preferred a four-coordinate square-planar geometry.
• Rh(III) exhibits promising NMR spectroscopic properties, suggesting it as a viable alternative to Cu(II).

Conclusions:

• Rh(III) is a potential substitute for Cu(II) in NMR studies of the human prion protein's copper-binding region.
• Preliminary experimental data support Rh(III) coordination, though further investigation is needed to detail the interaction mode.